New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1887-08-08
HIGH SPEED ON THE OCEAN.
PROBLEMS OF MARINE PROPULSION.
POSSIBILITY THAT STEAMSHIPS MAY BE BUILT TIC
pIvXI LILLE RAs1 ExPREss TRAINS


4some dav the world will wake mp and find that the
science of marine propulsion has been only half devei
oped" said marine engineer az he looked ont OF MS
Office window afternoon last week. and barred MS
head to the that up from the harbor coveen
with steamers.
How can that be asked reporter who was enjoy
ing the with him. Hasn't everything been done
that can be done with the present known means I"
~Don't he so of that yong man. was the reply
at Am not n wild schemcr or an idle dreamer butyo
know IL IS the unexpected that always happens. The
history of engineering would seem to snow 'hat
every expcdent has tried, you say Millions OF
dollar. have been expended in more or less suocess
and vet the history OF every art shows that
the most intelligent workers will tumble over the
biggest discovery Of their dig under 1t and walk all
around IL for years. bssf Ignorance that 1t thore'
right under their waiting for the lucky dscoverer
Much greater progress has been made In rapid ocomo
ton on land than on water and yet in some ways the
problem on land presents the greater difficulties
Enormous power has to be squeezed into compara-
lively small locomotive. limit Is set to size by the
crushing strength of rails and the elastic strength oi
bridges And then, II unlimited power he given there Is
limit TO speed the tendency 10 jump the track due
to the rapid motion OF the unbalanced parts OF tho
engine and the inability to get around curves INC
Atlantic liner has grades curves to overcome;
she carries power and yet she numbers along
t twenty miles an nour, while tho express trair makes
fifty"
Why Is the limit much lower In ono case than IN
the other Z" asked the listener. as he watched the
steamer Pilgrim rounding the Battery with all her ont
ing flying.
to vessels progress increases AS the square OF ner
speed When begins TO roll mp waves 1t jumps up 10
the third fourth power While the locomotive mas the
solid earth a fulcrum. the steamship has only the
yielding water This gives way and the result Is what
is known among marine engineers rs slip; much OF
al Tho nnnlli m N
common uso-the paGde-wneel and the scre~-are also
wastefuI. The common form of whe-l. with rigid
paddles or buckets Is extremity uneconomical. When
the bucket touches the water IL Is going down and
Il hounds the water downward. When most deeply i'm
mersed IL Is accng horizontally desired but for the
rest OF its stroke Is wasting force in lifting water up
TIE screw Its power in churning mp the water
in sending IL Of centrifugaly. instead OF attending to
business and driving 1t straight back and the ship
straight forward The actual observed efficiency OF the
best forms OF screw determined by 500 experiments
made by Messrs. Thornycrof the famous torpedo boat
builders OF England 60 per cents the highest only
20 per cent Tho total of all tue losses ocls up TO
large per cent Twenty years ago Mr.. Froude. an
English engineer. made series OF experiments with H.
NJ = Vulture and reported TO tho Lords OF the Adni-
rally the rc.stances which sne encountered In moving
through the water speeds and the proportion
which work thus done bore To the work developed IN
her engines The Vulure towed by another
speed ii was easy to calculate the work done. The
OF the engines of deter mined by
them. IL found that only 40 per cent oil
tho power developed in her engine cyUners was use
fully employed IN propellng the vessel. Rauchfuss
German engineer worked out formula fro the data
derived from froudes experiments lie applied 1t TO all
the in German Navy. AMI found that their
ecenees varied from - 10 % per cent: or TO put
the other way that from 80 to Is cent Of tho power
OF their engines dead loss"
But, dropping the question OF efficiency isn't 1t posi-
BILE The power and get much higher Speeds
let it cost wat 1t may +"
"To u limited eKtent-yes. Beyond that, with the
present hods-no The efficiency OF the paddle wheel
can be somewhat increased by having feather n, 1t
Is termed-hat u.s. nttng the buckets with such regai-
apparatus that they viii present their faces snarey
water pushing II straight back Instead OF pound
ing aud lifting IT, This device Is much used In England.
but 1t has never been favored In this country fhe
buckets Liable 10 got out OF order aud the Ice of our
rivers and harbors would wreck thom In tue hrst milo
from the wharf.
Moreover. when the screw or the paddle wheel gets
beyond certain size. the material Is not strong enough
TO stand the strain. IA uso twenty i've
feet la diameter. Much beyond th. II would be duicut
TO go Then the shaft the most dlrat VI all parts 10
Construct. becomes ThI. Professor rhurston
recently sEetched his idea OF ship sixth OF mile
long, which could carry power sufficient to drive hor
forty hour. aud Ite LOadoh EhgiHocr. In an
ayLns his plans. showed that the propeller shau would
he five feet in diameter and weigh 500 tons and
that the largest steam cylinders made. twenty-five
OF them would have coupled this nghty snan.
and they would take up $50 feet OF the ships
length When the weight OF machinery n thus In
creased and 1t at high speeds IL would rack the
vessel 10 pieces Tho shafts now used on our ocean
steamships large IS 20 tesi the iorgers ability
and machinery to the Utmost No; with the present
clumsy machinery for transmitting the force generated
In the boilers - the wafer that serves as fucram'
there little hope for further advance Some one must
strike out IN line There - that Nv eragc loss OF
per which shall bc the heritage OF the lucky in
yentor who design simple, direct acting appir-
atns. that shall make every pound OF steam do tie tu
duty In driving the ship And when such an apparatus
Ia iscovcrcd will he compact In form aud eiuabe
in action three our perhaps ten times the power
now possible may be applied This. with the stopP.ge
of all leaks and losses Will send the big steamer Of the
future along rate OF which its land rival the limited
express would not Ice ashamed"
May there he great improvements In the form OF
the present screw J." asked the reporter see what
that French engineer accomplished by putting new
screw La Champagne. IL makes two or three Knots
difference In her speed. the officers say"
"Yes. but st within narrow limits" was the answer
" There is more technical nonsense talked about the
correct form Of aud less really known about IT,
than with any other part OF the subject The
ost .ucc.ssful designer Of propeers that
lived. Mr. tfrif1thk, WIN designed those urod
in the Engsh hayy, didn't pretend to know anything
about IT, lie simply tined al ssrts and hook the that
worked be. The Why be hit upon the disiiprtve type
which bear. his name charlottesville of his mctbods
Having losure time he hogan experimenting 10
Determine much work each part Of the blade
dId lie put spherical boss about the hub. extending
out third Of the screws radius .hus covering up
third Of ench blade He expected that thus about third
OF the screws usefulness would BE- impaired but To his
aslonishIDeut II more powerful than before. Then
he turned blades around sticking the broad end into
the huh and leaving the marrow end pointing out
This did bete than ever. and prolonged series OF ex
peTmepis failed 10 discover anything much superior 10
his form on which he stumbled 40 bndly Almost the
las, words hr Grths spoke on thus subject that
four nat blades stuck In hub will give within a few
per cent OF the efficiency of the most scientifically de-
signed screw. Another instance showing Tow little Is
known about the matter Is that OF large English
of war ! forget her name. that WAS built with four
bladsI screw She developed a certain speed. few
months after she WIS put in commission an accident
broke two ~ the blades and strgitway she walked of
al speed knots better than sue had done he